Patterned transparent films have been used in many parts of display devices such as spacers, insulating films, and protective films, and many positive photosensitive compositions have heretofore been proposed for these applications (for example, see JP Sho 51-34711 A, JP Sho 56-122031 A, and JP Hei 05-165214 A).
In general, electronic parts, such as thin-film transistor type liquid crystal display devices and solid-state image sensing devices are provided with insulating films for insulation between electric wirings arranged in layers. A positive photosensitive composition that allows the formation of an insulating film having a desired pattern by a small number of steps has been widely used as a material that forms the insulating film. The positive photosensitive composition is required to have a wide process margin in the process of forming an insulating film. Further, an insulating film or a display device using the positive photosensitive composition may be in contact with a solvent, an acid, an alkali solution, or the like by, for example, dipping and treated with heat in a post-production process.
In recent years, there also exists an application of further forming an inorganic film on a transparent film formed (patterned transparent film) under high temperatures. In this case, the inorganic film to be formed is formed by means such as chemical vapor deposition or sputtering. In order to obtain a film of good quality by one of those film formation methods, high temperatures of 300° C. or more are required in a film formation process in some cases. That is, the transparent film (patterned transparent film) serving as a ground for the inorganic film is also exposed to high temperatures in some cases. When the transparent film (patterned transparent film) serving as a ground for the inorganic film has insufficient thermal resistance, desorption gas is produced owing to thermal decomposition of the transparent film (patterned transparent film) during a high temperature process, and the inorganic film of good quality is not obtained because of the influence of the desorption gas. In addition, thermal deterioration causes coloring in the transparent film (patterned transparent film), resulting in difficulty in the use of the resultant film for transparency applications. Because of those reasons, a positive photosensitive composition having high thermal resistance to a temperature of 300° C. or more has been demanded.
Some proposals have been made as positive photosensitive compositions provided for those applications. For example, there are proposed a material containing a siloxane polymer and a naphthoquinone-based photosensitizing agent, and a material in which a siloxane polymer, an imide compound, and a naphthoquinone-based photosensitizing agent are mixed (see, for example, JP 2006-178436 A and JP 2009-15285 A). Films made from those materials each had a problem in that fully satisfying crack resistance, high transparency (transmittance and transparence), and other required characteristics was difficult in a film formation process under a condition of high temperatures of 300° C. or more.